1. Field of the Invention
The present invention relates to a biopsy forceps and more specifically to a biopsy forceps having an elongate tubular body assembly which includes a high torque transmitting portion and a flexible tip or end portion.
2. Description of the Prior Art
Heretofore, various biopsy forceps have been proposed and are in wide use in obtaining a biopsy tissue sample. Such biopsy forceps typically include a coil spring guide wire extending between a handle portion and a forceps assembly. The forceps assembly includes a body that is fixed to the distal end of the coil spring guide wire. A stylet or control wire is received within the lumen of the coil spring guide wire and is connectable to a trigger member movably mounted within the handle portion of the biopsy forceps to which the proximal end of the coil spring guide wire is coupled.
A pair of movable forceps are mounted to the body of the forceps assembly, and to the control wire, such that forward movement of the control wire causes the forceps to move outwardly away from each other and rearward movement of the control wire causes the forceps to come together and capture tissue therebetween.
In the use of such a biopsy forceps, rotation of the handle portion results in some twisting of the coil spring guide wire and the transmission of torque to the coil spring guide wire.
At times body fluids and blood can pass through space between adjacent coils of the coil spring guide wire, and gain access to the biopsy forceps, contaminating same.
Examples of previously proposed biopsy instruments, including biopsy forceps, are disclosed in the following U.S. Pat. Nos.:
______________________________________ U.S. Pat. No. Patentee ______________________________________ 3,964,468 Schulz 4,646,751 Maslanka 4,655,219 Petruzzi 4,721,116 Schingten et al ______________________________________
The Maslanka U.S. Pat. No. 4,646,751 discloses a biopsy forceps including an operating cable which is surrounded by a cable jacket, the cable jacket being in the form of a coiled spring. The cable jacket is surrounded by a plastic covering. In the disclosed biopsy forceps, a fluid inlet tube is provided for introducing cleaning fluid into the interior of the cable jacket.
As will be described in greater detail hereinafter, the biopsy forceps of the present invention differs from the previously proposed biopsy forceps by providing a torqueable and formable elongate body assembly which includes, according to one aspect, a coil spring guide wire with a first tubing or covering which is provided over a proximal portion of the coil spring guide wire, and which has high torque transmission characteristics, and, according to a second aspect, a second tubing or covering which is provided over a distal or tip portion of the coil spring guide wire, and which is made of a formable material and placed on the coil spring guide wire in a tight manner which gives the distal portion of the coil spring guide wire with the second tubing or covering thereon a high degree of formability.